The purpose of this invention is to provide a toothbrush production method with which it is possible to combine the necessary mechanical properties/strength quality with transparency. The toothbrush comprises: a head part (2) having a bristle-implanted surface (20) on the tip side; a handle part (7) including a grip part (8), and that is positioned further towards the rear end than the head part; and a neck part (4) that is positioned between the bristle-implanted surface and the handle part, and that is deformed by external force exerted upon the head part. The toothbrush production method includes a step for filling using a resin material via a gate part positioned at a predetermined position. The gate part is positioned further towards the tip than the grip part.